#include<iostream>
using namespace std;
#include<functional>
void test01()
{
	plus<int>n;//加法仿函数
	cout<<"50+40=" << n(50, 40)<<endl;

    minus<int> m;
    cout<<"29 - 12 = "<< m(29,12)<<endl;
    
 
	negate<int>c;//取反仿函数
	cout << "-90的取反结果为" << c(-90);
		
 
}
int main()
{
 test01();
}